1. Field of the Invention
The present invention relates to a 4-cycle engine.
2. Description of the Related Art
In recent years, a 4-cycle engine with two cylinder axes disposed in a V-shape has been proposed, which includes an electronically controlled type fuel injection system (for example, see Japanese Utility Model Application Laid-open No. 127779/90). In this engine, a substantially Y-shaped distributing type intake pipe is disposed inside a V-bank, and a single injector is disposed upstream from a junction of the intake pipe to supply a fuel.
In the above prior art engine, no special consideration is taken into account for reducing the size of an intake device upstream from the injector and thus, there is a problem that an engine becomes large due to such intake device.
In general, a 4-cycle marine engine is used in an environment which promotes rusting more than for an engine for a motor land vehicle and thus, many parts of aluminum alloy and stainless steel are employed. For example, a cam pulley forming a portion of a valve-operating system is made of aluminum alloy. Therefore, in order to take out a spark timing pulse from the rotation of the cam pulley, a metal piece of a magnetic material is secured to an inner peripheral surface of a rim portion of the cam pulley, and a pick-up coil is disposed so that it is opposed to the metal piece.
With the above construction, however, only one piece of magnetic material is attached to one cam pulley. For example, in a 4-cycle engine including an electronically controlled type fuel injection system, it is difficult to take out a timing pulse for injection of a fuel in addition to the above-described spark timing pulse.